Buggy code:
public class Tree extends Composite { int modelHandle ; int checkRenderer ; int columnCount ; int ignoreTextCell ; int ignorePixbufCell ; TreeItem [ ] items ; TreeColumn [ ] columns ; ImageList imageList ; boolean firstCustomDraw ; static final int ID_COLUMN = 0 ; static final int CHECKED_COLUMN = 1 ; static final int GRAYED_COLUMN = 2 ; static final int FOREGROUND_COLUMN = 3 ; static final int BACKGROUND_COLUMN = 4 ; static final int FONT_COLUMN = 5 ; static final int FIRST_COLUMN = ( Tree . FONT_COLUMN ) + 1 ; static final int CELL_PIXBUF = 0 ; static final int CELL_TEXT = 1 ; static final int CELL_FOREGROUND = 2 ; static final int CELL_BACKGROUND = 3 ; static final int CELL_FONT = 4 ; static final int CELL_TYPES = ( Tree . CELL_FONT ) + 1 ; public Tree ( Composite parent , int style ) { } static int checkStyle ( int style ) { } boolean checkData ( TreeItem item ) { } protected void checkSubclass ( ) { } public void addSelectionListener ( SelectionListener listener ) { } public void addTreeListener ( TreeListener listener ) { } int calculateWidth ( int column , int iter ) { } public Point computeSize ( int wHint , int hHint , boolean changed ) { } void copyModel ( int oldModel , int oldStart , int newModel , int newStart , int [ ] types , int oldParent , int newParent , int modelLength ) { } void createColumn ( TreeColumn column , int index ) { } void createHandle ( int index ) { } void createItem ( TreeColumn column , int index ) { } void createItem ( TreeItem item , int iter , int index ) { } void createRenderers ( int columnHandle , int modelIndex , boolean check , int columnStyle ) { } void createWidget ( int index ) { } GdkColor defaultBackground ( ) { } GdkColor defaultForeground ( ) { } void deregister ( ) { } public void deselectAll ( ) { } void destroyItem ( TreeColumn column ) { } void destroyItem ( TreeItem item ) { } GdkColor getBackgroundColor ( ) { } public TreeColumn getColumn ( int index ) { checkWidget ( ) ; if ( ! ( ( 0 <= index ) && ( index < ( columnCount ) ) ) ) <START_BUG> error ( ERROR_CANNOT_GET_ITEM ) ; <END_BUG> return columns [ index ] ; } public int getColumnCount ( ) { } int [ ] getColumnTypes ( int columnCount ) { } public TreeColumn [ ] getColumns ( ) { } TreeItem getFocusItem ( ) { } GdkColor getForegroundColor ( ) { } public int getGridLineWidth ( ) { } public int getHeaderHeight ( ) { } public boolean getHeaderVisible ( ) { } public TreeItem getItem ( Point point ) { } public int getItemCount ( ) { } public int getItemHeight ( ) { } public TreeItem [ ] getItems ( ) { } TreeItem [ ] getItems ( int parent ) { } public boolean getLinesVisible ( ) { } public TreeItem getParentItem ( ) { } int getPixbufRenderer ( int column ) { } public TreeItem [ ] getSelection ( ) { } public int getSelectionCount ( ) { } int getTextRenderer ( int column ) { } public TreeItem getTopItem ( ) { } int gtk_button_press_event ( int widget , int event ) { } int gtk_button_release_event ( int widget , int event ) { } int gtk_changed ( int widget ) { } int gtk_key_press_event ( int widget , int eventPtr ) { } int gtk_motion_notify_event ( int widget , int event ) { } int gtk_row_activated ( int tree , int path , int column ) { } int gtk_test_collapse_row ( int tree , int iter , int path ) { } int gtk_test_expand_row ( int tree , int iter , int path ) { } int gtk_toggled ( int renderer , int pathStr ) { } void hookEvents ( ) { } int indexOf ( TreeColumn column ) { } boolean mnemonicHit ( char key ) { } boolean mnemonicMatch ( char key ) { } int paintWindow ( ) { } int pixbufCellDataProc ( int tree_column , int cell , int tree_model , int iter , int data ) { } void register ( ) { } void releaseItem ( TreeItem item , int [ ] index , boolean releaseResources ) { } void releaseItems ( TreeItem [ ] nodes , int [ ] index ) { } void releaseWidget ( ) { } public void removeAll ( ) { } public void removeSelectionListener ( SelectionListener listener ) { } public void removeTreeListener ( TreeListener listener ) { } void resetCustomDraw ( ) { } public void setInsertMark ( TreeItem item , boolean before ) { } public void selectAll ( ) { } void setBackgroundColor ( GdkColor color ) { } int setBounds ( int x , int y , int width , int height , boolean move , boolean resize ) { } boolean setCellData ( int tree_model , int iter ) { } void setFontDescription ( int font ) { } void setForegroundColor ( GdkColor color ) { } public void setHeaderVisible ( boolean show ) { } public void setLinesVisible ( boolean show ) { } void setScrollWidth ( int column , int iter ) { } public void setSelection ( TreeItem [ ] items ) { } public void setTopItem ( TreeItem item ) { } public void showColumn ( TreeColumn column ) { } public void showSelection ( ) { } void showItem ( int path , boolean scroll ) { } public void showItem ( TreeItem item ) { } int textCellDataProc ( int tree_column , int cell , int tree_model , int iter , int data ) { }

Fix:
error ( ERROR_INVALID_RANGE ) ;